Either the Undo Add Cell command doesn't appear at all, or it appears in the Edit menu but doesn't do anything! Of course, one can just Delete the added cell, but his makes it hard to undo a number of changes and then, possibly, redo them.

There's a related bug that's rather minor: After doing Insert Cell , the undo command reads Undo Add Cell rather than Undo Insert Cell . It does work, however, unlike the same Undo Add Cell command when it actually belongs there!